Official WebsiteScreenshot:

CamDesk: The Webcam Desktop Widget

CamDesk is a free, open source, desktop webcam widget, that was originally created mainly as a desktop surveillance system to see who's coming to the door, while on the computer. Although other users have used it for other purposes. Like using CamDesk alongside
CamStudio for screencasting.
NOTE: You can download the source code from the website linked at the top of this post.
Windows Requirements:
- Windows 2000/XP/Vista/7 - 32bit
- 1.17MB of hard disk space
- Webcam
- Webcam Drivers
- .NET Framework 4.0
Linux Requirements:
- 7.4KB of hard disk space
- Python, PyGTK
- V4L
- GStreamer
- Webcam
- libgtk2.0-dev
- libgtk2.0-doc
- libglib2.0-doc
